One species of dihydroxyaryl fluorene, 9,9-bis(4-hydroxyphenyl) fluorene (BHPF), has been used previously for the manufacture of thermoplastic condensation polymers. For example, BHPF was used in the manufacture of polycarbonates for optical disks, in Japanese Patent No. 1-124358. BHPF has also been incorporated into polyester polymers (See U.S. Pat. No. 4,925,913, and P. W. Morgan, "Aromatic Polyesters with Large Cross-Planar Substituents," Macromolecules 3:536-544, 1970.).
The brittleness of bisphenol fluorenone (i.e. BHPF) thermoplastic carbonate polymers was noted in Kambour, et. al., "Tough Transparent Heat- and Flame-Resistant Thermoplastics via Silicone Block-Modified Bisphenol Fluorenone Polycarbonate," J. Applied Polymer Sci., 20:3275-3293 (1976).
Crosslinkable moieties were incorporated into carbonate polymers to be used in surface lamination of thermoplastic materials, in patent application No. WO 93/25607. BHPF was mentioned in that patent as one monomer which could be used to manufacture carbonate polymers for use in structures with a crosslinkable surface layer and a thermoplastic core layer.
It would be desirable to have an improved crosslinkable carbonate polymer possessing a good combination of product properties including impact resistance, solvent resistance, optical clarity, resistance to melting at high temperatures, and physical strength.